What challenges does layered architecture solve in complex software?

Complex architecture means the biggest challenge will be the execution (implementation) and ongoing maintenance. With a layered approach, there is enough encapsulation between major components, and these individual components can be easily designed, built, scaled, and maintained in the long run.

Uma das mais vista, se n?o a mais posta em pratica, a arquitetura em camadas é adotada quando se n?o se tem uma complexidade a ser atendida através do software, nela você poderá separar cada contexto de forma clara, desacoplada e da fácil manuten??o, partindo deste pensamento, caso o core precise atender a mais features, integra??es, será necessário repensar a remodelar o modelo adotado.

If we use a layered approach then it becomes really easy to maintain the existing code and also makes it easy to test. MVC is one of the best examples for this.

Code reusability in a layered architecture offers numerous advantages, including reduced development time and effort, enhanced maintainability, and improved quality and reliability. By leveraging pre-written, tested components, developers can avoid redundant work, ensuring consistency and stability across different layers and applications. This leads to fewer bugs and easier maintenance, as updates to reusable components benefit all systems using them. Additionally, reusable code contributes to scalability, as it can be optimized for performance and adapted more easily.

Layered Architecture helps in Code reusability by having code/services built in each layer in micro service patter. Maintaining abstraction can further increase the code reusability, and help in building composable layered architecture.

For example in a typical mvc application would have controller layer along with filter and decorators that can protect any unauthorized access and ensure security thought the application.

The layered architecture separates concerns by isolating different functionalities into distinct layers, such as presentation, business logic, and data access. This isolation allows for more targeted security measures. For instance, the data access layer can have strict security protocols to protect sensitive data, while the business logic layer can enforce business rules and authentication checks. By compartmentalizing security responsibilities, it becomes easier to manage and implement comprehensive security strategies, reducing vulnerabilities and enhancing overall system security.

Layered architecture facilitates unit testing by allowing each layer to be tested independently. Mocking and stubbing can be used to simulate interactions between layers. Testing is simplified because developers can focus on specific layers without worrying about the entire system. For example, the business logic can be tested independently of the data access layer, ensuring that each layer performs correctly. This modular approach reduces the complexity of test cases, increases test coverage, and makes it easier to identify and fix issues. It also supports continuous integration and deployment practices by enabling automated testing of isolated components.

Layered architecture delineates clear boundaries between different layers, enabling different teams to work on separate layers with well-defined interfaces. This separation fosters better collaboration by allowing teams to specialize in different aspects of the system. For instance, front-end developers can focus on the presentation layer, while back-end developers concentrate on the business logic and data access layers. Clear interfaces and contracts between layers minimize dependencies and integration issues, facilitating smoother collaboration. It also enhances parallel development efforts, as changes in one layer have minimal impact on others, reducing the risk of conflicts and ensuring a more efficient development process.